Mobile phones together with its Bluetooth and wired headsets have become very popular lately. By using mobile phones people can receive phone calls in different uncontrolled locations such as train, road, restaurant, gymnastic club, home, office, private rooms such as toilets, etc.
Similar situation can be occurred with wireless phone like DECT that are very popular in home and office environment.
As soon as a user answers a call of a mobile phone (denoted as party 1 or ‘receiving party’), the mobile phone microphone pickups the voice of party 1 combined with the background sounds at his location. This mixed signal is transmitted by the phone to the other party (denoted as party 2). This mixed signal may expose to party 2 the background sounds of the environment of party 1 which may disclose some information about the location of party 1.
In some cases people would like to keep their privacy and not to disclose to others where they are located. To overcome this issue in some cases the receiving party (i.e. party 1) will reject the call and will initiate the call later. In other cases the receiving party will answer the call hoping that no background sound will be heard and disclose his location, if a background sound starts during the call it can embarrass party 1.